The meeting on Monday evening, which was granted upon Ashton's request, a presidential source said, offered an opportunity for the envoy to see first-hand that Morsi, who has been kept at an undisclosed location since his ouster on 3 July, “is in a good condition and is being well-treated.”

Informed sources told Ahram Online that Ashton's message to Morsi and his fellow Muslim Brothers would be one of “concession.”

“I think it is safe to say that she and the entire world is aware that we cannot reverse the course of developments and things have to go forward,” an informed source said. “What she talked about was how to move things forward.”

Ashton arrived in Cairo late on Sunday after preliminary talks with interim Vice President Mohamed ElBaradei. The talks came after close to 80 Morsi supporters were shot dead by police at their sit-in in Cairo's Nasr City on Saturday.

This is Ashton's second visit to Cairo in two weeks. But unlike last time, this time she made progress on two matters: meeting Morsi and extracting a commitment from the state authorities and the Brotherhood leadership that they would both act to avert more violence.

Prior to leaving Cairo on Tuesday, Ashton is expected to make a short statement about the killings and to call on all sides to refrain from violence and engage in a constructive political process to reinstate democracy.

“We are not sure what she will say exactly or whether she will speak in Cairo or after she leaves,” a Cairo-based European diplomat said. “But yes she will tell the world that Morsi is fine and that there is an awareness on the side of all concerned parties that peaceful engagement has to be the rule.”

Ashton is in town, diplomats said, to represent both the EU and the US. “She reflected an awareness that she knows Morsi's ouster might not have met the exact democratic criteria but it was a reflection of the will of the Egyptian people,” a presidential source said.

Egyptian and European sources said it is clear that Morsi cannot be re-instated as president – not even in a symbolic fashion in which he would delegate his powers to a consensus prime minister as has been suggested by Islamist figure Selim El-Awa. Morsi, the same sources said, would not be able to leave custody before legal charges against him are dropped. This goes for the other arrested Brotherhood leaders, the same sources added.

"We believe these charges are for the most part politicised and Cathy Ashton made it clear that a transparent litigation process is in order here," said another Cairo-based European diplomat. He added that Egyptian authorities had promised to take steps in that direction “only after” the sit-ins are dispersed peacefully.

The police have said there is enough public support for them to end the two major pro-Morsi sit-ins in Cairo and Giza despite Saturday's bloodshed.

European diplomats said further arrests of Brotherhood leaders would be reconsidered and strictly limited to those accused of inciting violence.

The same diplomats added that the Egyptian authorities had promised to revisit decisions to suspend the airing of Islamist TV channels and the freezing of the financial assets of some Islamist figures “after the sit-ins are peacefully dispersed” – and provided that neither the channels nor the assets are used to incite violence.

Meanwhile, Ashton received repeated commitments from Egyptian authorities that presidential elections would be held with one year with international monitoring.